Will new controller solve problem?

My water well stopped operating and pressure dropped to near zero. I opened the circuit breaker and removed the cover from the controller. It is a Square "D" 20/40 230v unit. The contacts were open. I manually closed them, and then reset the breakers. The pump operated. At 42#, I went to the breaker box and opened the breakers. The pressure by then had reached 50#. I opened the water supply and dropped the pressure to 40#. The contacts never opened. The pressure held at 40#. Am I safe to assume that replacing the controller will solve the problem, or might there be something else contributing to the controller failure?

Thank you speedbump. This unit was in the house when I moved in eight years ago. I just finished replacing the controller with a new one for less than $18. It works, so it is a cheap fix if it holds out. The pressure tank seems to be working OK.

By the way, the old controller was a Pumptrol Class 9013 FSW 2 Form P.

The usual cause of your problem is that the switch (controller) doesn't see/read the pressure change, increase or decrease, in real time or at all. That lag in time causes the pump not to come on or shut off when it is supposed to.

The cause of that is a blockage of water pressure to the switch; a blocked switch nipple or tubing and its fittings (on jet pumps with the switch mounted on the motor) is the usual cause.

So changing the switch probably loosened, dislodged or opened the blockage some and it can block again.